Efficiency
Efficiency, in this case — the ratio of the power of the power supply (see "Power") to its power consumption. The higher the efficiency, the more efficient the power supply, the less energy it consumes from the network at the same output power, and the cheaper it is to operate. Efficiency may differ depending on the load; the characteristics can indicate both the minimum efficiency and its value at an average load (50%).
It should be noted that compliance with one or another level of 80PLUS efficiency directly depends on this indicator (for more details, see "Certificate").
Fan size
The diameter of the fan(s) in the power supply cooling system.
The large diameter allows to achieve good efficiency at relatively low RPMs, which in turn reduces noise and power consumption. On the other hand, large fans are more expensive than small ones and take up a lot of space, which affects the dimensions of the entire PSU. We also emphasize that a small fan is not yet a sign of a cheap power supply — quite advanced models can also have such equipment, in order to reduce dimensions.
As for specific diameters, the smallest value that can be found in modern consumer-grade PSUs is
80 mm. The most popular option is
120 mm, this size gives good efficiency and a relatively low noise level at a reasonable price and dimensions. Larger diameters are somewhat less common —
135 mm and
140 mm.
Certification
The presence or absence of an 80+ certificate for the power supply. This certificate indicates high energy efficiency: to obtain it, the efficiency (see above) must be at least 80%, and in different modes (20%, 50% and 100% of the maximum load). There are several degrees of 80+:
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80+. The original version of the certificate, assuming an efficiency of at least 82% (at least 85% for 50% load).
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80+ White. The second name of the original 80+ certificate (see above).
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80+ Bronze — efficiency not less than 85% (for half load — 88%).
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80+ Silver — respectively 87% (90% for half load).
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80+ Gold — 89% (92% for half load)
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80+ Platinum — 90% (94% for half load).
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80+ Titanium — 94% (96% for half load).
The power factor (see "PFC Type") must be at least 0.9 for the lower levels and at least 0.95 for the Platinum level. Also note that for redundant power used in server systems, the efficiency requirements are somewhat lower.
Cybenetics Efficiency
Cybenetics Efficiency is a power supply unit (PSU) energy efficiency certification system that serves as an alternative to the 80 PLUS standard. It is more accurate as it considers efficiency at various load levels (10%, 20%, 50%, 100%) and at different input voltages (115V, 230V). The labeling of this system is identical to 80 PLUS:
Bronze — overall efficiency from 82% to 85% at 115V input voltage and from 84% to 87% at 230V;
Silver — 85 – 87% and 87 – 89% respectively;
Gold — from 87% to 89% (115V) and from 89% to 91% (230V);
Platinum — 89 – 91% at 115V and 91 – 93% at 230V;
Titanium — 91 – 93% (115V) and 93 – 95% (230V);
Diamond — ≥ 93/95%.
Cybenetics Noise
The Cybenetics Lambda certification system evaluates the noise level of power supplies (PSU), providing consumers with information about their acoustic characteristics. As a result, you can rely not only on the efficiency of the power supply but also on its noisiness. There are the following Cybenetics Lambda certification levels:
Standard — from 40 dB(A) to 45 dB(A) – noticeable noise;
Standard+ — from 35 dB(A) to 40 dB(A) – distinct noise;
Standard++ — from 30 dB(A) to 35 dB(A) – moderate noise;
A- — from 25 dB(A) to 30 dB(A) – moderately quiet;
A — from 20 dB(A) to 25 dB(A) – quiet;
A+ — from 15 dB(A) to 20 dB(A) – very quiet;
A++ — less than 15 dB(A) – virtually silent.
ATX12V version
A standard for power supplies that supplements the ATX specifications regarding power supply along the 12 V line. Introduced into use since the time of the Intel Pentium 4 processor. In the first series of the standard, the +5 V line was mainly used; from version 2.0, the +12 V line was introduced to fully power the components computer. Also in the second generation, a 24-pin power connector appeared, used in most modern motherboards.
EPS12V version
The version of the EPS12V standard that the power supply complies with. The EPS12V standard was created primarily for high consumption PCs (with a power of more than 700 W, see "Power") and entry-level servers. Such power supplies have a 24-pin plug for the motherboard and an 8-pin processor power connector (sometimes more than one, see “MB / CPU Power” for more details). They are also more reliable than ATX12V. They are compatible with most ATX standard motherboards, however, in older motherboards, there may be problems with matching connectors, so this issue should be clarified separately (however, to solve this problem, in some power supplies, parts of the plugs are made removable, which allows them to be reduced if necessary to the dimensions of the connectors on the motherboard).
SATA
The number of SATA power connectors provided in the PSU.
Nowadays, SATA is the standard interface for connecting internal hard drives, and it is also found in other types of drives (SSD, SSHD, etc.). Such an interface consists of a data connector connected to the motherboard, and a power connector connected to the PSU. Accordingly, in this paragraph we are talking about the number of SATA power plugs provided in the PSU. This number corresponds to the number of SATA drives that can be simultaneously powered from this model.
MOLEX
The number of Molex (IDE) connectors provided in the design of the power supply.
Initially, such a connector was intended to power peripherals for the IDE interface, primarily hard drives. And although the IDE itself is completely obsolete today and is not used in new components, however, the Molex power connector continues to be installed in power supplies, and almost without fail. Almost any modern PSU has at least
1 – 2 of these connectors, and in high-end models this number can be
7 or more. This situation is due to the fact that Molex IDE is a fairly universal standard, and with the help of the simplest adapters, components with a different power interface can be powered from it. For example, there are Molex - SATA adapters for drives, Molex - 6 pin for video cards, etc.